code: def setUp(self):
      super(ExtraFunctionsTestCase, self).setUp()
  
      # 1 - 2 - 4 - 5
      # 3 _/     \_ 6 - 7
      self.graph = OrderedDict(
          [
              (1, [2]),
              (3, [2]),
              (2, [4]),
              (4, [5, 6]),
              (6, [7]),
              (5, []),
              (7, []),
          ]
      )
  
file_path: neupy/tests/layers/graph/test_extra_functions.py
imports: from collections import OrderedDict
  from neupy.layers.graph import find_outputs_in_graph, topological_sort, filter_graph, is_cyclic, lazy_property
  from base import BaseTestCase
label_desc: Use image node_id 1 for calling the ExtraFunctionsTestCase obj's underlying member method code with example usage: obj.setUp() without return types